This proposal is for a one-and-a-half year feasibility study, largely methodological, to determine how a population of high risk adolescents, for whom extensive and detailed information regarding matters of health and behavior have already been collected, can best be followed-up to trace the role of social, psychological, and biological factors in the development of drug behavior. Specifically, this research will build upon data collected between 1968-70, through personal interviews and medical examinations with a community representative cross section of 752 adolescents aged 12-17. These data regarding health status (physical and emotional), growth and development, psychosocial, and background characteristics provide the baseline or first wave of this longitudinal study. The research proposed here will determine optimum procedures for the full-scale follow-up, by interviewing the oldest segment of the original sample -- the 141 youths who were ages 16-17 at first interview. The major objectives are: 1) To determine how well different methods of data collection work, most importantly: specially recruited and trained young interviewers from the community vs. interviewers with the usual qualifications (matched for race and sex in both cases); self-answering vs. interviewer-asked questions about drug behavior; 2) To serve as phase one of the follow-up study by preparation the listed sample with up-to-date addresses and developing as well as administering the new interview schedule; 3) To prepare the detailed proposal for the full follow-up, especially the hypotheses, procedures, analytic design and cost estimates based on experience in the feasibility study.